Process of and apparatus for extracting sulphur from ore



Aug. 24, 1937. H. M. CROWTHER 2,090,667

PROCESS OF AND APPARATUS FOR EXTRACTING SULPHUR FROM ORE Filed Jan. 7, 1936 INVENTOR. l

Patented Aug. 24, 1937 UNITED STATES PROCESS OF AND APPARATUS FOR EX- TRACTING SULPHUR FROM ORE.

Henry M. Growther, Los Angeles, Calif.

Application January 7 3 Claims.

Generally stated, the object of the invention is to provide an improved process and apparatus by which a given amount of sulphur ore, (usually 1000#) that has been previously crushed sulficiently so that the largest size pieces will pass the perforations of a one half inch mesh screen, is charged into an open-top cylindrical container which by the means provided is then lowered into and submerged in about five tons of molten sulphur contained in a tank having live steam heating drums also submerged in the sulphur bath to keep it at about 300 degrees Fahrenheit, and such immergence of the ore liquefies all of the elemental sulphur contained in the ore charge within about 15 minutes, whereupon, by the means provided the ore container is raised above the level of the, molten sulphur bath (but not above the rim of the submergence tank) and immediately the ore container is given one minute of rotation at about 1000 R. P. M., which action centrifugally throws out fully 95% of the sulphur content of the ore, which liquefied sulphur during the rotary motion passes through the perforations of the double, spaced outer walls of the ore container, but in getting free is compelled to pass through a partition composed of metallic lead-wool which strains out all of the solid impurities and delivers commercially pure sulphur into the supply of molten sulphur in the sub- 0 mergence tank, from which the excess outlets through an overflow conduit at any desired level. Means are provided whereby this system of treatment is accomplished without necessity of handling the hot ore containers, and also with- 35 out loss of heat, as sulphur cools rapidly and cannot be given more than about 25 degrees of excess heat beyond its fusion point without injury to the quality-of the product, which is the reason for applying the centrifugal extraction cycle immediately, and within the submergence tank without uncovering the tank for this purpose. The use of lead-wool is a special feature as it is not attacked by the sulphur and thus has an extra long life in the use employed. The invention does not consume any water (the live steam being used in return circuit) which is frequently a great advantage where water is not plentiful. The remarkably high recovery of the sulphur 50 accomplished by the invention renders the discharge of the tailings more convenient ascustomarily 10% or more of the sulphur is lost in the tailings by ordinary steam retorting methods depending on gravity fiow of the sulphur from 55 the ore, and this excess loss of sulphur tends to 1936, Serial No. 57,955

cement and cake the tailings in the treatment container. 7 i

I attain these objects by the mechanism illus#- trated in the accompanying drawing, in which:

Fig. 1 is a front elevation, in part sectionalized,

of a sulphur extracting apparatus embodying the principles of the invention.

Fig, 2 is a top View plan of the rotary ore container. 7

Similar numerals refer to similar parts throughout the two views. As illustrated the invention comprises a circular metal tank 2, within which are positioned, and disposed near the walls of the tank a series of closed live-steam drums 3 which, in each case receive their hot steam supply from a boiler source (not shown) by way of the connected pipes shown, each of which passes through the tank bottom to which each steam drum is anchored in leak proof manner. The tank is provided with an outlet pipe 4 which is arranged as an overflow when tank is filled with molten sulphur to a certain fixed level, and this overflow pipe takes its load from the tank bottom but is prevented from acting as a syphon by the air vent 4A which, however may be capped and thus converting the overflow system into a syphon for purpose of draining the tank if desired at any time. Centrally anchored to the bottom of the tank on the outside is the guide 5, equipped with a leak-proof packing gland, in which the solid rod 6 operates as a lift powered by the hydraulic cylinder I that receives its power from a source not illustrated; and this solid lift-rod has a fixed disc 8 anchored thereto positioned inside of the tank bottomand serving as a rod movement limit. The ore charge for treatment is loaded into the open-top cylindrical container [0, and fixed centrally to the bottom, on the inside is the spindle seat 9 whichjournals on the spindle end of the hydraulic lift-rod and in this manner the ore container is rotatably mounted and used in manner that will be more fully explained. The ore container has a perforated outer wall II, and a similarly perforated, spaced inner wall l2, and between these two concentric spaced walls is the spacer l3 which is removable, and sandwiched between the described spaced double walls is the partition or filling composed of metallic lead-wool serving as a molten sulphurfilter. Oppositely positioned, in gravity dumping location are fixed the dumping lugs l5, operable as explained later..

The tank is previously filled with a charge of molten sulphur to thelevel'of the dotted line l6, and kept molten by the st'eamheating drums means 25, illustrated. W

The upper end of the rotor shaft 26 engages the rotor drive pulley2'l which is drivenby a quarter turn belt from a friction clutch drivingpulley, not shown; and the rotor drive pulley is retained against up and downmovement by the cage 28 for the reason that in operationyduring the introduction of the ore container'into the sulph l nbath tank, and its removal therefrom for dumping, the'rotor drive shaft must slide longitudinally through the drive pulley, and to permit of thismovement a long key-way 29 is formed in the drive shaft but the drive pulley remains at all times slidingly keyed to theshaft by the fixed key 30 anchored in the pulley, bore HA pair of oppositely positioned dumping chairs 3| are provided to dump the tailings load of a treated charge by'seating the dump pins of the container into arecess of the chairs, which operationwill be more fully described.

I In operating the process the tank is filled to its overflow level with pure molten sulphur and kept at propertemperature by applied steam heat, then the hydraulic lift rod is operated to raise the rotor plate five feet above the top of the tank and the rotor plate and its frame is locked at such point so as to give ample working room, then the ore container is readyfor posi- "tio'ningf on the spindle end of the hydraulic lift .rod Whichis done by lowering the spindle-and mountin'gthe ore container thereon and lower- ,ingthe'container into the tank until its top is level with the top. of the tank whereupon the container is loaded with ore'from a dump car, .and. the container now loaded with a charge of ore is at once lowered by reversing the hydraulic lift until submergedin the molten sulphur bath, and immediately the rotor is lowered so that its plate closes the tank opening. After submerfgence of about 15 minutes the native sulphur of the ore charge will be completely liquefied, then the hydraulic lift is operated to raise the top rim of the ore container against the rotor which rotor assembly has about 100# of weight not counterbalanced and this provides ample friction to drive the container whenthe clutch of the rotor drive pulley is thrown in, whereupon the container, now above the level of the sulphur bath, is rotated at high speed for one minute and then the rotor drive clutch is released and as soon as the container movement ceases the hydraulic lift is operated to raise the ore container and the rotor assembly, at this timeresting on the top rim of the container, to a height 'of six feet abovethe top rimiof the sulphur bath tank at which point, out of the way, the rotor sliding carrier is locked, and the hydraulic lift is reversed to lower the-container sufficiently to set its dumpingaxle-pins in.place in the seats of the dumping chairs, (fixed to the top, of the tank, and arranged to-swingdnto, and out of commissionl whereupon the hydraulic lift again. is

lowered sufficientlyto clear the container bottom and leave the container free to swing on its dumping trunnion system to a dumping position by reason of the overbalanced load in relation to its point of rotation, and thus the load of exhausted tailings is discharged into a dump-car, which, with itstrack is not illustrated, and after righting the container while still resting on the chairs the hydraulic hoist is raised to again seat the container on its spindle rod and the container is again lowered until its toprim is level withthe tank top when it is again loaded with a fresh charge of ore from a dump-car and then .again lowered to submerge the container and its load of ore in the molten sulphur bath in the tank, and the rotor assembly is allowed to lower by gravity to its position of rotation closing the tank: opening, and ready to whirl the container after its bath, and repeat the cycle again and again continuously.

By providing some five tons of molten sulphur as a bath into which at fifteen minute intervals only o'ne half aton of cool oreis submergedthe resulting lowering of the temperature of the bath is minimized within practical range, and-with sufficient heat continuously supplied tothe molten bath, ore may be treated in the manner'described, continuously. It will be understood that in addition to; using a bath of molten sulphur as a'heat conducting agency for melting the sulphur of the ore being treated, the inventional'so uses simultaneously with the operation of removing the sulphur, a great excess of molten sulphur as a method of adding to the efliciency of the centrifugal whirling action practiced within the melting chamber or tank.

Itis understood that usually a multiplicity of the units described will be employed, each unit treating about-twotons of ore per hour if half ton loads are us ed.; I Y a Various changes may be made without departing from the spirit and scope of the-invention.

I claim: 1; A process for extracting elemental sulphur from ore, comprising the placing of a load of sumciently crushed ore in a container having perforated walls equipped with a filtering medium, and lowering the ore-loaded container to complete submergence in molten sulphur contained in. a tank equipped with a removable cover and provided with facilities to maintaingthe molten sul-' and thereafter raising the ore-containerbymeans provided, free from the molten sulphur, and as soon as it is so raised rapidly rotating the container, by means provided, to cause the now molten sulphur of the ore, together with the excess sulphur of the submergence tobe thrown c en-- trifugally throughthe filter covered perforations ,of theore-container to simultaneously filter the sulphur from the waste gangue or tailings and the basic principleof passing through thefiore effect a high degree of extraction inthe form of commercially pure sulphur. i

2 In apparatus for extracting sulphur from cm, the combination of a tank equipped with removable cover, and suitable for containing molten sulphur at atmospheric pressure; means of heating and maintaining the sulphur ina properly cess accumulation of ore-recovered sulphur; and provided with a movable, filter-walled ore-container equipped with lead-Wool filtering medium, and having means provided for lowering the loaded ore-container into the molten sulphur, and

sulphur which is maintained in a properly molten condition at atmospheric pressure, and without the addition of other reagents; and then removing the sulphur content of the ore thus rendered molten, together with any molten sulphur adhering to the charge from the submergence operation, while the molten sulphur being recovered is continually maintained, by heat provided and applied, in a heat liquefied condition, by means of centrifugal filtration employed at atmospheric pressure immediately upon removal of the ore from its treatment submergence by means provided.

HENRY M. CROWTI-HER. 

